Bonding sleeve for a medical device

ABSTRACT

A medical device delivery system comprises an inner tube, a medical device disposed about a portion of the distal region of the inner tube, a medical device sheath disposed about the medical device, a medical device sheath retraction device extending proximally from the medical device sheath and an outer sheath disposed about a portion of the medical device sheath retraction device. The distal end of the outer sheath terminates at least one medical device length proximal of the medical device. The medical device sheath is movable relative to the outer sheath and relative to the inner tube.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of and claims priority to U.S. patentapplication Ser. No. 10/066,994, filed Feb. 4, 2002, issued as U.S. Pat.No. 7,785,340, the entire contents of which are hereby incorporatedherein by reference.

FIELD OF THE INVENTION

This invention relates to catheters used for multiple procedures,including for delivering medical devices, such as stents, and a methodof making the catheter systems. The delivery system employs a sleevewhich aids in the bonding of parts of the catheter and is capable ofbecoming a part of the final system product.

BACKGROUND OF THE INVENTION

Catheters are used for many medical purposes. The present invention isnot limited to a specific type of catheter, rather a method of makingthe catheter and the resulting product. Examples of catheters andprocedures are addressed below for the sake of background.

In typical PTA or PTCA procedures, a guiding catheter is percutaneouslyintroduced into the cardiovascular system of a patient and advancedthrough the aorta until the distal end is in the desired (coronary)artery. Using fluoroscopy, a guide wire is then advanced through theguiding catheter and across the site to be treated in the coronaryartery. An over the wire (OTW) balloon catheter is advanced over theguide wire to the treatment site. The balloon is then expanded to reopenthe artery. The OTW catheter may have a guide wire lumen which is aslong as the catheter or it may be a rapid exchange catheter wherein theguide wire lumen is substantially shorter than the catheter.Alternatively, a fixed wire balloon may be used. This device features aguide wire which is affixed to the catheter and cannot be removed.

To help prevent arterial closure, repair dissection, or preventrestenosis, a physician can implant an intravascular prosthesis, or astent, for maintaining vascular patency inside an artery or other vesselat the lesion.

Stents are also used for a variety of other purposes includingmaintaining the patency of any physiological conduit including arteries,veins, vessels, the biliary tree, the urinary tract, the alimentarytract, the tracheobronchial tree, the genitourinary system, and thecerebral aqueduct.

The stent may either be self-expanding or balloon expandable. For thelatter type, the stent is often delivered on a balloon and the balloonis used to expand the stent. The self-expanding stents may be made ofshape memory materials such as nitinol or constructed of regular metalsbut of a design which exhibits self expansion characteristics.

The present invention is directed to the area of constructing cathetersand other medical devices such as described above. Each catheter hasmany parts which must be interconnected with high accuracy andprecision. Typically parts are adhered or thermally bonded together.Using retaining sleeves as an example (examples of which may be found inU.S. Pat. No. 4,950,227, U.S. Pat. No. 6,221,097, U.S. Pat. No.6,068,634, U.S. Pat. No. 5,980,530, U.S. Pat. No. 5,968,069 and U.S.Pat. No. 5,044,726), welding may be accomplished by heating theretaining sleeve or by applying laser radiation to the retaining sleeveat a wavelength absorbed by the retaining sleeve. CO₂ lasers have provento be particularly useful in this regard. Adhering and Welding methodsare well known in the industry. An example of the use of laser weldingmay be found in U.S. application Ser. No. 09/684,255.

All US patents and applications all other published documents mentionedanywhere in this application are incorporated herein by reference intheir entirety.

Without limiting the scope of the invention in any way, the invention isbriefly summarized in some of its aspects below.

SUMMARY OF THE INVENTION

The present invention is directed to using a sleeve to hold parts andjoints of a catheter together such that they may be bonded together,wherein the sleeve remains on the catheter after the bonding to formparts of the final catheter product. With thermal bond welding, thesleeve is aligned and heat shrunk on the catheter to constrain theindividual parts of the medical device, after which they are bonded inplace. Instead of removing the sleeve, it remains to form part of themedical device. The sleeve which remains may form a useful part or anon-useful part which does not adversely affect the use of the medicaldevice. As will be discussed below, the sleeve may vary in length alongthe catheter, providing for various final parts. In typical embodimentsthe sleeve, or at least a portion of the sleeve, is considered to benon-removable.

Initially, the sleeve is positioned over and around the catheter partsto be bonded together or to be encapsulated. A heating unit is used toapply heat to the sleeve to shrink it on the catheter. Heat, or anyother method used to shrink the sleeve, is applied to one spot and thengradually moved along the length of the sleeve, gradually removing airand space between the sleeve and the catheter parts. The parts of acatheter then are bonded together via known techniques, such asadhesion, thermal welding, RF welding and ultrasonic welding. Portions,or all, of the sleeve are welded onto the catheter as well. After thebonding is complete the sleeve of the present invention remains in placeproviding an additional part, such as stent retaining sleeves, a distaltip or a protective cover. This eliminates the step of removing theholding sleeve in the normal process, saving time and finances.

The invention also contemplates certain coatings, pastes, gels or filmsmay also be employed to constrain and/or form parts during bonding andbecome a part of the finished bonded component.

The invention is not limited to catheters. It may be applied to othermedical items which use sleeves of the like to hold parts of the medicalitems together in order to bond them. Catheters are only used in thedescription for examples purposes.

The disclosure below involves simplifying the process of bondingconstruction as well as providing new methods of forming required partsof medical devices.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional view of the distal end of a catheterillustrating a particular embodiment of the invention;

FIG. 2 is a cross-sectional view of the distal end of a catheterillustrating a further embodiment of the invention;

FIG. 3 is a cross-sectional view of the distal end of a catheterillustrating a further embodiment of the invention;

FIG. 4 is a cross-sectional view of the embodiment shown in FIG. 3,having the balloon in expanded form;

FIG. 5 is a cross-section view of the embodiment of FIG. 1, wherein thesleeve is being heat shrunk onto the catheter;

FIG. 6 is a cross-section view of a catheter mid-shaft to be bonded;

FIG. 7 is a cross-section view of a portion of a rapid exchange catheterillustrating a further embodiment;

FIG. 8 is an exploded cross-section view of a portion of a rapidexchange catheter illustrating a further embodiment;

FIG. 9 is an exploded cross-section view of a portion of a rapidexchange catheter illustrating a further embodiment;

FIG. 10 is an exploded cross-section view of a portion of a rapidexchange catheter illustrating a further embodiment;

FIG. 11 is a cross-sectional view of the distal end of a catheterillustrating a further embodiment of the invention; and

FIG. 12 is a cross-sectional view of the distal end of a catheterillustrating a further embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

While this invention may be embodied in many different forms, there areshown in the drawings and described in detail herein specificembodiments of the invention. The present disclosure is anexemplification of the principles of the invention and is not intendedto limit the invention to the particular embodiments illustrated.

For the purposes of this disclosure, the term stent refers to stents,stent-grafts, grafts and other endoluminal prostheses whetherself-expanding, balloon expandable, self-expanding and balloonexpandable or otherwise expandable as are known in the art.

In addition to the over-the-wire embodiments (example also found in U.S.Pat. No. 5,980,533) shown in the figures, the inventive catheter systemand methods may also be provided in any catheter system, such as plainballoon angioplasty catheters and rapid-exchange configurations.Examples of rapid-exchange catheters may be found in U.S. Pat. No.5,534,007 and U.S. Pat. No. 5,833,706. The inventive stent deliverysystems may also be made in fixed wire form. Examples of fixed-wirecatheters may be found in U.S. Pat. No. 5,702,364.

The system may be adapted for use with a medical device such as a stent,for example, a self-expanding, balloon expandable or combinationself-expanding and balloon expandable stent. The system may also be usedfor delivery of other medical devices for use in the body as wellincluding, but not limited to, ultrasonic devices, laser devices, venacava filters, drug coated sleeves and other implantable drug deliverydevices and the like.

The inventive medical systems disclosed herein may also be provided withany of the features disclosed in U.S. Pat. No. 6,096,056, U.S. Pat. No.6,068,634, U.S. Pat. No. 6,036,697, U.S. Pat. No. 6,007,543, U.S. Pat.No. 5,968,069, U.S. Pat. No. 5,957,930, U.S. Pat. No. 5,944,726, U.S.Pat. No. 5,653,691 and U.S. Pat. No. 5,534,007.

The stent delivery system may also comprise various coatings as areknown in the art, including lubricious coatings to facilitate movementof the various parts of the system, as well as collagen-type coatings.More information concerning suitable coatings may be found in U.S. Pat.No. 5,443,907, and U.S. application Ser. Nos. 08/382,478, 09/306,939 and09/316,502.

The invention is also directed to medical device delivery systems andcatheters produced using the inventive methods.

For the purposes of the detailed description of the invention, figuresof a portion of the distal end of a typical balloon catheter will beused. It should be understood, as mentioned above, that the presentinvention is applicable to other portions of the catheter as well asother medical devices, which use a constraining sleeve for bonding partsand joints together. It should also be understood that the materialsused may be any of those materials known in the art where applicable.

For the purposes of this disclosure, unless otherwise indicated,identical reference numerals used in different figures refer to the samecomponent.

FIG. 1 illustrates the distal end of a typical balloon catheter 10 fordelivering stent to a specific location within the body. The catheter 10has an outer sheath 12 which extends over the body of the catheter 10.The catheter also comprises an inner shaft 14 forming an inner lumen 18,which allows access for a guide wire 15. A balloon 16 is mounted on thecatheter 10 at the distal end. The proximal end of the balloon 20, inthis type of catheter, is bonded to the distal end 22 of the outersheath 12 at point 24. In other embodiments, the proximal end of theballoon may also be bonded to the inner shaft. The catheter is typicallyguided through a guide catheter 53 (shown in FIG. 4).

The distal end of the balloon 26 is mounted on the inner shaft 14 andwill eventually be bonded to the inner shaft 14 at point 28. There is adistal tip 30 at the distal end of the catheter, but, as will beexplained later, it may not be needed due to the forming of a distal tipby the sleeve 32 (hereafter called sleeve 32). Marker bands 31 are alsoillustrated.

The sleeves of the present embodiments suitably comprise non-crosslinked thermoplastics, such as olefins and tecothanes, so that bondingand flowing is enhanced.

The parts of the catheter to be made are held together via the sleeve32. As mentioned above, the sleeve 32 is heat shrunk around the parts tobe permanently bonded to constrain them in place as a bonding aid. Thisis done typically at 200-250EF, however, the material dictates thetemperature. In this instance, as shown in FIG. 5, a heating element 41,such as a heat gun, a hot block or hot jaws, is used to apply heat to apoint 43 on sleeve 32. The heating element can be applied directly onthe surface of the sleeve 32. The heating element 41 can be then movedalong the length of the sleeve 32, as shown, causing the sleeve 32material to shrink, and optionally flow. Depending on the type ofheating element used, movement may not be needed. The temperature isdictated by the material used. The heat must be sufficient to shrink thesleeve, but not so hot as to break the material down so as to destroythe integrity of the sleeve. By heating the material at or slightlyabove its melt temperature, the material will flow and create a fusebond where bonds are desired.

This bonding may be dictated by the part which is being made. Forexample, in the case of forming a stent retaining sleeve, it may bedesirable to only bond a part of the sleeve, leaving the remainingportion shrunk but not bonded. This allows the stent retaining sleeve tobe capable of moving relative to the balloon for effective release ofthe stent during delivery. Complete bonding of the parts together atdesired spots can be completed during the welding procedures.

The moving heating element seals the sleeve 32 to the catheter, holdingthe parts of the catheter together. The longitudinal moving of theheating element and the flow of the sleeve 32 material stretches thematerial out and removes any air pockets to result in a tight, uniformfit. The shrinking of the sleeve 32 can start at one end of the sleeve32, proceeding to the opposite end. However, it is contemplated that theshrink may start at any place along the sleeve, gradually movinglongitudinally.

The bonding of the parts of the catheter is then started, suitably doneby laser welding. The sleeve remains as part of the final product and insome cases can be used to hold a loaded stent in place duringsterilization. In FIG. 1, sleeve 32 remains to form the distal tip ofthe catheter. In all cases, the sleeve may also act as an addedprotective layer and be lubricated for easy movement through bodylumens.

The port 34 of the inner lumen 18 may be closed due to the heat shrunksleeve 32 until needed. If the catheter were a back loaded catheter, asshown, the guide wire 15 would pierce the closed port when needed.

A sleeve 55 may also be used to secure the marker bands 31 to the innershaft 14 during the securement of the marker bands 31 to the shaft 14.Sleeve 55 remains a part of the catheter and may be a soft protectivecover over the marker band 31 to protect the balloon 16 from beingdamaged by the marker bands 31. Sleeve 5 may be used in any of theembodiments.

In the embodiment shown in FIG. 2, a larger sleeve 36 is used. The wordlarger is used in terms of length of coverage over the catheter. Inaddition to the functions of sleeve 32, as described above, sleeve 36also forms a distal stent retaining sleeve 38. As mentioned above, stentretaining sleeves are known. The materials and methods for applying andusing the sleeve 32 are similarly applicable here. Retaining sleeve 38can aid in holding the stent 40 in place.

The invention also contemplates a sleeve which may extend up the conesof the balloon, but not over the end of the stent. Such a sleeve may aidin balloon rewrap as well as provide leading lubrication for thecatheter to aid in trackability of the stent.

The use of retaining sleeves to retain a stent on a catheter has beendisclosed in a number of patents including U.S. Pat. No. 4,950,227 toSavin et al., U.S. Pat. No. 5,403,341 to Solar and U.S. Pat. No.5,108,416 to Ryan et al., as well as U.S. Pat. No. 5,944,726 and U.S.Pat. No. 5,968,069. One or more retaining sleeves typically retain thestent on the catheter when the stent is in an unexpanded state. Uponexpansion of the stent, the retaining sleeves release the stent.

FIG. 3 illustrates another embodiment. The method of applying the stentis the same. In this embodiment, an even larger sleeve 42 is used. Inaddition to the function of sleeves 32 and 36, as described above,sleeve 42 also forms a proximal stent retaining sleeve 44 which extenddown the proximal end of the balloon 16, over the balloon waist 20. Itshould be understood that, the sleeve 42 may extend further in theproximal direction to provide for bonding at point 24. In thisembodiment, sleeve 42 covers the entire balloon section, as well as thestent 40.

As described above, sleeve 42 constrains the parts of the catheter inthis area until they are fully bonded, such as through laser welding. Aswith the other sleeves, sleeve 42 remains in place for sterilization anduse. As part of the final catheter, sleeve 42 forms a distal tip 46, adistal stent retaining sleeve 48 and a proximal stent retaining sleeve44. Sleeve 42 also forms a tubular member 50 which surrounds the stent.This member may be used in the final product or discarded, according tothe application. To allow the stent to eventually be separated from thecatheter the stent retaining sleeves 44, 48 are separated from thetubular member 50 by tear away perforations 52. The tubular member 50also may be drug eluting. It should be understood that an embodiment maycomprise a catheter wherein the heat shrinkable sleeve covers the stent,but only provides one stent retaining portion, and therefore only onecircumferential perforation.

FIG. 4 shows the embodiment of FIG. 3 wherein the guide catheter 53 iswithdrawn and the balloon 16 is expanded. As can be seen, the retainingsleeves 44, 48 tear away, or are peeled, from the tubular member 50 andfall away from the stent 40. The tubular member 50 must be made from amaterial which can expand with the stent.

If the tubular member 50 is meant to be left in the body, it preferablyshould be biocompatible. In such a case, the stent effectively pushes itinto the artery wall. Biocompatible materials are well known in the art.They include, but are not limited to TEFLON and urethanes. The materialmay further include pharmaceutical agents to prevent restenosis. Suchagents may comprise proteins with small molecules, such astaxol-containing drugs, nucleotides and actinomycine. Materials whicheventually dissolves or disintegrates may also be used, such aspolylactic acid. The tubular material 50 may also incorporated drugswhich aid in the healing and acceptance of the stent, such asanti-thrombogenic agents. These types of agents are well known.

Teflon or a fluoropolymer may also be used for the tubular member 50 toprotect against hyperplasia or restenosis. The member prevents thevessels from growing back in on the delivered stent.

The present invention contemplates a multi-material sleeve 42, which ispre-assembled. In such a sleeve, the retaining sleeve portions 44, 48may be made of a material which has less elasticity than the tubularmember. The sleeve 42 may vary in other characteristics as well, such aslubricity and strength.

It should be understood that the invention contemplates the use of thesleeve in any welding application. FIG. 6 shows the process of acatheter midshaft bonding between a proximal shaft 64 and a distal shaft62. Shaft 64 may be a metal hypotube. The ends of the shafts are fittedonto a mandrel 68 for support. In accordance with examples of themethods, a support mandrel may be used as support for other parts to bebonded together. A sleeve 66 is shrunk around the junction to be bonded.The sleeve 66 is then bonded to shafts 64, 62, providing a tightconnection. The sleeve allows for a connection which does not requirethat the shafts overlap, as seen in FIG. 1 at 24, and thus a smoothinner transition. It should be understood that the connection at 24 mayalso be created by this method.

FIGS. 7-10 illustrate the use of a sleeve 84 in connecting and sealingbetween a mid-shaft 72, a distal shaft 74 and a distal inner shaft 76,which functions as a guide wire lumen, in a rapid exchange catheter.Rapid exchange catheters are well known in the art. These catheters aregenerally characterized in that a port 78 allows for insertion ofcertain parts from the outside of the catheter to the inside anywherealong the length of the catheter. In typical rapid exchange catheters,the port is for insertion of a guide wire or an inflation lumen. Onlythe portion showing the port 78 and connection between the mid-shaft 72,distal shaft 74 and distal inner shaft 76 is shown.

FIG. 7 shows the distal end 82 of the mid-shaft 72 inserted into theproximal end 80 of the distal shaft 74. It should be understood that thedistal shaft 74 could be inserted into the midshaft 72 in an invertedmanner. A port 78 is positioned in the wall of the distal shaft 74and/or the wall of the midshaft, depending on the port s positioning. Inthis particular embodiment, the port 78 opens into a guide wire lumen76, which is bonded to the distal shaft 74 and extends distally to theend of the catheter. A sleeve 84 is shrunk around the juncture of theshafts 72, 74. The shafts are then bonded together.

The sleeve 84 also allows for a connection between the shafts 72, 74with a smooth internal transition, as shown in FIGS. 8-10. In theseembodiments, as with the embodiment shown in FIG. 6, the ends 82, 80 ofthe shafts 72, 74 are adjacent, but not overlapping. The shrunken sleeve84 is used to connect the shafts 72, 74. The shafts 72, 74 need not bebonded directly to each other. Instead, the sleeve 84 may be bonded toeach shaft.

FIGS. 8-10 also show various positions of the port 78. FIG. 8 shows theport 78 in the proximal end 80 of the distal shaft 74, FIG. 9 shows theport 78 in the distal end of the midshaft and FIG. 10 shows the port 78being formed in the ends 80, 82 of both shafts 74, 72.

FIG. 11 illustrates a further embodiment of the invention. Thisparticular embodiment comprises a balloon 16 attached to the catheter, aproximal stent retaining sleeve 44 and a distal stent retaining sleeve42, an outer sheath 12, a stent 40 and a proximal shrunken sleeve 100and a distal shrunken sleeve 102.

The invention contemplates incorporating the proximal sleeve 100 or thedistal sleeve 102 or both. As can be seen, the balloon is positioned onthe catheter and then the stent retaining sleeves 108, 110 arepositioned. The stent retaining sleeves may extend beyond the ends ofthe balloon, as shown with sleeve 110, to the ends of the balloon, asshown with sleeve 108, or they may stop short of the ends of theballoons. It should be understood that the ends of the balloon 104 andthe outer sheath 22 may overlap in either manner. Only the manner inwhich the balloon end overlaps the sheath end is shown.

In this particular embodiment, the shrunken sleeves 100, 102 are shrunkdown over these junctures. The bonds are then welded into place and thesleeves 100, 102 are left in place. Arrows 111, 112 illustrate thepreferred direction in which the sleeves 100, 102 are welded.

FIG. 12 illustrates an alternative juncture configuration between thestent retaining sleeve, the balloon and the outer sheath. In thisparticular configuration, end of the balloon 104 does not overlap theend 22 of the outer sheath 12. The stent retaining sleeve 108 extendsbeyond the end of the balloon and over or under the end of the outersheath. The shrunken sleeve 100 is then shrunk down over the junctureand the components are then welded, as discussed above.

For the examples shown, the medical balloon may be made of any suitablematerial including Pebax. Other suitable materials are disclosed in U.S.Pat. No. 6,024,752, and U.S. Pat. No. 6,036,697.

For the examples shown, suitable materials for the outer sheath/shaftare well known in the art and include high density polyethylene (HDPE)and SURLYN and those materials disclosed in U.S. Pat. No. 6,036,697 andU.S. Pat. No. 5,543,007.

The effectiveness of the bonding may be limited by the compatibility ofthe adjacent materials. Adjacent materials which provide covalentbonding or molecular entanglement are examples of suitable material.

For the examples shown, the inner shaft may be made of a flexibleconstruction having any collapse strength. The inner shaft may also bemade of an incompressible construction, such as a polymer encapsulatedbraid or coil. The flexibility of the braid/coil allows the medicaldevice delivery system to navigate through body lumens and theincompressibility of the braid/coil aids in maintaining the integrity ofthe system and aids in deployment accuracy when during release of themedical device. The braid/coil may be comprised of stainless steel ornitinol, but desirably stainless steel encased in a polymer such as apolyimide, HDPE, Teflon or urethane, but desirably polyimide or Teflon.Other suitable materials which may be used are well known in the art.

Portions of the sleeves may be radio opaque for the user to track thepositioning within the body. Methods of making the sleeve material radioopaque are well known. Suitable examples include doping the raw materialwith radio opaque materials.

The above sleeves also provide strain relief on joint of the catheter bydiffusing the strain placed upon the catheter during storage and use.

Portions of the sleeves may be removed while other portions aremaintained as part of the final catheter when desired.

The sleeve may also take the form of a film/coating, paste or gel.Typically, this embodiment may be used in parts of catheters which arenot subject to a significant degree of contraction or pressure, such asa distal tip. A spray producing a dried film can be used, providingadequate axial resistance for welding purposes. Suitable materialsinclude urethanes, polystyrenes and polyesters. For pastes or gels,suitable ground up micro particles are dissolved and applied to themedical device where needed. Axial resistance is provided with timedrying or via a catalyst.

The medical device delivery systems may be subjected to additionalprocessing steps prior to and/or subsequent to disposing the retainingsleeve about the stent and balloon. For example, bumpers and/or markerbands may be disposed about the inner tube or other portions of themedical device delivery system. A retractable sheath may be providedover the balloon and stent. A manifold may also be provided at theproximal end of the medical device delivery system. Other additionalsteps include providing to the inventive medical device delivery devicesany of the features disclosed in U.S. Pat. No. 6,096,056, U.S. Pat. No.6,007,543, U.S. Pat. No. 5,968,069, U.S. Pat. No. 5,957,930, U.S. Pat.No. 5,944,726 and U.S. Pat. No. 5,653,691.

In addition to being directed to the embodiments described above andclaimed below, the present invention is further directed to embodimentshaving different combinations of the dependent features described aboveand/or claimed below.

Every patent, application or publication mentioned above is hereinincorporated by reference.

The above examples and disclosure are intended to be illustrative andnot exhaustive. These examples and description will suggest manyvariations and alternatives to one of ordinary skill in this art. Allthese alternatives and variations are intended to be included within thescope of the claims, where the term “comprising” means “including, butnot limited to”. Those familiar with the art may recognize otherequivalents to the specific embodiments described herein whichequivalents are also intended to be encompassed by the claims. Further,the particular features presented in the dependent claims can becombined with each other in other manners within the scope of theinvention such that the invention should be recognized as alsospecifically directed to other embodiments having any other possiblecombination of the features of the dependent claims. For instance, forpurposes of claim publication, any dependent claim which follows shouldbe taken as alternatively written in a multiple dependent form from allprior claims which possess all antecedents referenced in such dependentclaim if such multiple dependent format is an accepted format within thejurisdiction (e.g. each claim depending directly from claim 1 should bealternatively taken as depending from all previous claims). Injurisdictions where multiple dependent claim formats are restricted, thefollowing dependent claims should each be also taken as alternativelywritten in each single dependent claim format which creates a dependencyfrom a prior antecedent-possessing claim other than the specific claimlisted in such dependent claim below (e.g. claim 6 may be taken asalternatively dependent from any of claims 2-5, claim 4 may be taken asalternatively dependent from claim 3; etc.).

1. A method of making a catheter, comprising the steps: providing ashaft having a proximal region and a distal region; providing a balloonon the distal region of the inner shaft; placing a retaining sleevehaving a length and a first and second end around at least a portion ofthe balloon and the shaft; heat shrinking the retaining sleeve; securingthe balloon to the shaft; and then sterilizing the catheter with atleast a portion of the retaining sleeve remaining shrunk around thecatheter.
 2. The method of claim 1, wherein the retaining sleeve, atleast in part, forms a distal tip.
 3. The method of claim 1, wherein theretaining sleeve comprises a thermoplastic polymer which issubstantially not cross-linked.
 4. The method of claim 3, wherein thethermoplastic polymer is chosen from the group consisting of olefins,polyesters and urethanes.
 5. The method of claim 1, the retaining sleevebeing gradually heat shrunk along its length around the balloon andshaft.
 6. The method of claim 1, wherein the retaining sleeve is formedfrom a material chosen from the group consisting of a liquid film,wherein the film solidifies prior to the bonding of the balloon to theshaft or a gel, wherein the gel hardens prior to the bonding of theballoon to the shaft.
 7. The method of claim 5, the balloon having aproximal cone and waist, a distal cone and waist and a body portionthere between, wherein the length of the retaining sleeve extends atleast partially over the distal cone portion of the balloon.
 8. Themethod of claim 7, wherein the length of the retaining sleeve extends atleast partially over the body portion of the balloon and is capable ofbeing used as a first stent retaining sleeve.
 9. The method of claim 8,further comprising the step of loading a stent on the body of theballoon, such that the retaining sleeve at least partially covers thestent.
 10. The method of claim 7, wherein the length of the retainingsleeve extends at least partially over the proximal cone of the balloon.11. The method of claim 10, further comprising the step of loading astent on the body of the balloon under the retaining sleeve, theretaining sleeve comprising a proximal portion, a distal portion and acenter portion, wherein the center portion may be torn away from thedistal and proximal portion when the balloon expands and wherein thedistal and proximal portions form first and second stent retainingsleeves, respectively.
 12. The method of claim 1, the balloon having adistal region and a proximal region, wherein the proximal region of theballoon is positioned adjacent to the distal region of the shaft andwherein the retaining sleeve is placed over a portion of the balloon andshaft.
 13. The method of claim 12, wherein the balloon and the shaftabut each other.
 14. The method of claim 12, wherein the ends of theballoon and the shaft overlap.
 15. The method of claim 12, the retainingsleeve being gradually heat shrunk along its length around the balloonand shaft.
 16. The method of claim 12, further comprising the step ofloading a stent on the body of the balloon, such that the retainingsleeve at least partially covers the stent, wherein the length of theretaining sleeve extends at least partially over the body portion of theballoon and is capable of being used as a first stent retaining sleeve.17. A catheter comprising: a shaft having a distal portion and aproximal portion; a balloon mounted around the catheter, said balloonhaving a proximal portion, a distal portion and a center portion; and aheat shrinkable sleeve shrunk onto the shaft, the heat shrinkable sleeveat least partially covering a portion of the distal portion of theballoon, wherein the balloon is secured to the shaft and the catheter issterilized and prepared to safely enter a body.
 18. The catheter ofclaim 17, wherein the distal end of the balloon is attached to thedistal end of the shaft.
 19. The catheter of claim 17, wherein the heatshrinkable sleeve forms a distal tip.
 20. The catheter of claim 17,wherein the at least a portion of the heat shrinkable sleeve is attachedto the catheter.
 21. The catheter of claim 17, the catheter furthercomprising a stent loaded on the center portion of the balloon, saidstent having a distal end and a proximal end, wherein the heatshrinkable sleeve extends over a portion of the stent.
 22. The catheterof claim 21, wherein the heat shrinkable sleeve extends over theproximal portion of the balloon.
 23. The catheter of claim 21, whereinthe heat shrinkable sleeve comprises perforations, such that when theballoon and the stent are expanded, the portion of the heat shrinkablesleeve which covers the stent breaks away with the stent.
 24. Thecatheter of claim 17, further comprising a marker band mounted on theinner shaft, within the balloon, and a second heat shrinkable sleeveshrunk around the marker band.
 25. The catheter of claim 17, wherein theshaft is an outer shaft, wherein the balloon has a proximal end, theproximal end of the balloon being secured to the distal end of the outershaft, wherein a portion of the heat shrinkable sleeve overlaps theproximal end of the balloon and the distal end of the outer shaft. 26.The catheter of claim 25, wherein the outer shaft does not overlap theballoon.
 27. The catheter of claim 25, wherein the outer shaft and theballoon overlap.
 28. The catheter of claim 25, further comprising astent retaining sleeve positioned within the retaining sleeve.
 29. Themethod of claim 17, wherein the heat shrinkable sleeve comprises athermoplastic polymer which is substantially not cross-linked.